Debug: No source available for "__floatdisf() at 0x800216e"

AKozarzewski · ‎2026-01-27

Split from old thread Debug: "No source available for main()"

This is not the same question.

Little late to the party but I have the same issue kinda. I switched to other branch in our project and I had the very same result. Then I took all suggested steps and I get when I tried to debug:

No source available for "__floatdisf() at 0x800216e"

Besides after switching to that branch program compiles just fine but doesn't work. All of this is of some settings that remained in project and weren't covered in git commit, but it's hard to commit every single file in CubeIDE enviroment. All important files were covered like all code files and ioc etc. i always switch when Cube is not running because it also creates issues. Any ideas?

AKozarzewski · ‎2026-01-28

Like I already said I did steps mentioned. I did got sure that I'm debugging debug compilation, not release, then I set these two optimisations accordingly.

Problem solved. For some unknown reason I had to enable again bin download in Debug Configurations in Startup section.

View solution in original post

Andrew Neil · ‎2026-01-27

@AKozarzewski wrote:
I have the same issue kinda.?

Not really.

The old thread was about not finding the source for main() - the user's own code

@AKozarzewski wrote:
I get when I tried to debug:
No source available for "__floatdisf() at 0x800216e"?

That's a compiler library function - not your own code.

You wouldn't expect to have the source for compiler library functions

Please give some more details about your project, and what steps you take to get that message.

How to write your question to maximize your chances to find a solution

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

Ozone · ‎2026-01-27

> Besides after switching to that branch program compiles just fine but doesn't work.

I think it would be helpful to provide a bit more information about what is not working.

As mentioned, most C-lib functions are not available in source, and thus not debuggable on C source level.
I think this is unrelated to the issue - but you can step through the assember instructions if needed.

Check were the application hangs, either by step-wise debugging, or retrospectively evaluate the SCB registers in case of a (hard-) fault.

AKozarzewski · ‎2026-01-28

Like I already said I did steps mentioned. I did got sure that I'm debugging debug compilation, not release, then I set these two optimisations accordingly.

Problem solved. For some unknown reason I had to enable again bin download in Debug Configurations in Startup section.

Andrew Neil · ‎2026-01-28

@AKozarzewski wrote:
Like I already said I did steps mentioned

But, as explained, those steps were for solving a different problem!

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

Ozone · ‎2026-01-28

I didn't follow the old thread, I suppose toolchain and debug environment are described there.

> I did got sure that I'm debugging debug compilation, not release, then I set these two optimisations accordingly.

Except for the missing debug symbols, this makes no difference. A "release version" can be debugged as well, as the debugger relies on hardware breakpoints (silicon support).

> For some unknown reason I had to enable again bin download in Debug Configurations in Startup section.

The debug information is contained in the ELF output file.
Perhaps your environment calls this "binary", as the object code is not ASCII as with HEX or S19..